title: Marine polysaccharide networks and diatoms at the nanometric scale.
abstract: Despite many advances in research on photosynthetic carbon fixation in marine diatoms, the biophysical and biochemical mechanisms of extracellular polysaccharide production remain significant challenges to be resolved at the molecular scale in order to proceed toward an understanding of their functions at the cellular level, as well as their interactions and fate in the ocean. This review covers studies of diatom extracellular polysaccharides using atomic force microscopy (AFM) imaging and the quantification of physical forces. Following a brief summary of the basic principle of the AFM experiment and the first AFM studies of diatom extracellular polymeric substance (EPS), we focus on the detection of supramolecular structures in polysaccharide systems produced by marine diatoms. Extracellular polysaccharide fibrils, attached to the diatom cell wall or released into the surrounding seawater, form distinct supramolecular assemblies best described as gel networks. AFM makes characterization of the diatom polysaccharide networks at the micro and nanometric scales and a clear distinction between the self-assembly and self-organization of these complex systems in marine environments possible.
authors.affiliation: Division for Marine and Environmental Research, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia. svetlicic@irb.hr.
authors.forename: Vesna
authors.initials: V
authors.lastname: Svetličić
authors.forename: Vera
authors.initials: V
authors.lastname: Zutić
authors.forename: Galja
authors.initials: G
authors.lastname: Pletikapić
authors.forename: Tea Mišić
authors.initials: TM
authors.lastname: Radić
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D017377:Diatoms / Q000378:metabolism*; D018625:Microscopy, Atomic Force / Q000379:methods; D011134:Polysaccharides / Q000378:metabolism*; D012623:Seawater
chemical_list: D011134:Polysaccharides